Body Swap
by ichihoe
Summary: Hanji's experiment goes "wrong" and now Eren and Levi are in each other's bodies.
1. Chapter 1

Looking at yourself from outside of your body must have been the strangest situation you could ever be placed in.

Eren was not looking into a mirror and suddenly noticing all of his facial flaws up close, but quite literally he was staring into his own teal-green eyes.

Or rather, at this point it wasn't his any longer. It belonged to none other than Lance Corporal Levi, and the Corporal was now in charge of what Eren's body did.

Levi blinked Eren's huge, doe-like eyes whenever nature planned for it, and Levi walked in Eren's body with Eren's legs. He kept Eren's back straight unlike Eren himself had done back in his own body, and he fed Eren's stomach when he grew hungry.

So how did the two end up in sexal activities like these? From normal, everyday actions to being involved together in a room with a bed, really did say something about their curiosity, didn't it?

However that was't the case. Corporal Levi claimed that this wasn't from curiosity, but it was for experimental purposes. (Eren had said that experiments were the results of curiosity, therefore that was why they were doing this in the first place- but Levi had shut him off with a glare. Eren didn't think he was capable of making such an expression.)

He was now, sitting on top of Levi (his own body to be exact) with a flushed face. He was fully exposed in all his naked glory, and so was the corporal underneath him.

It was definitely a strange thing to see your own body nude from another person's perspective. Eren hadn't even realized his penis curved slightly to the right until he had seen Levi take off his pants off Eren's body.

Eren didn't know what to expect when it was his turn to take off clothes from Levi's body. He had known that Levi was quite well-trained and despite his vertically challenged appearance, Levi was incredibly fit. Eren silently wondered what Levi thought of his body, but before he could even continue on with the thought he was being yelled at.

"Hurry up, shitty brat. Quit touching my body like that, it's revolting." Coming out of his own mouth with the harshness that could only belong to Levi, sounded strange. Thankfully they were both alone. "Your movements are lagging. What, are you savoring this?"

Sometimes Eren wished Levi would be more soft-spoken. But Eren knew better than that. Levi never sugar coated his words, and as cold as it was, it was endearing at the same time.

"N-no sir." Levi's voice echoed in his ear, and Eren could not get used to hearing it leave his own mouth. A stuttering Levi. You never heard that everyday.

"You're wasting time doing worthless shit. I despise wasting time. You could've taken three dumps during the time it took you to take off your pants. Are you suddenly feeling like a baby? Should I take off your clothes for you?"

So... How exactly did Eren end up in this mess?

* * *

A few days earlier, Eren had gotten an invitation from Hanji saying to meet her in her office.

He was in his own body during the time, and he had little to no knowledge of the fact that Hanji had also invited Levi over to her office as well.

He didn't even realize that her invitation was strange and a bit abrupt, because he hadn't even considered it. (Looking back, Eren wished he would have been more attentive on the details and decide not to go).

Eren stopped by the doorway- the door was left ajar- to see that Levi was already there. He stood in the far corner with his arms crossed over his chest, his expression its usual: the scowl. He looked displeased about something, and his eyes followed the test tube in Hanji's grip as she flailed about enthusiastically.

"Oh! Eren you're here!" Hanji said, stopping in her passionate speech to Levi to address Eren.

"Oi, shitty four eyes." Levi said, his tone dripping with irritation. Apparently he wanted to get some kind of point across, but Hanji prevented that from happening.

"Come inside, come inside!" Hanji chirped, making hand gestues for Eren to step into the room.

Eren felt hesitant in advancing, suddenly self-conscious about his movements. He was fully aware of Levi's piercing gaze on him, and he felt that if he did something wrong that Levi would not stop to think twice before giving a blow to Eren's head.

"I won't bite you! Come on then, Eren."

Eren couldn't help but feel a bit uncertain about her words. Even Levi looked as if he doubted her, the both of them sharing a moment of common knowledge that the exuberant scientist had more than enough competency to do something as crazy as that.

Finally Eren took a step forward, figuring he might as well do as told because he was invited over in the first place. "I, uh got your letter..." Eren said slowly, becoming wary of Levi's eyes on him. _But you never told me that Levi would be here as well!_

As if Levi had read Eren's mind, he asked "Why's the brat here? I told you that you're not allowed to stick knives into the kid."

"Good question. Drink this, and you'll find out." Hanji gave Levi the test tube. "And don't worry about a thing! No knives are involved this time."

Once again Eren found it hard to convince himself the opposite of Hanji's words.

"Hell no." Levi glared at the test tube in Hanji's hands.

Hanji didn't put up a fight. Instead, she turned to Eren with the test tube. "Eren, drink this."

"Okay-"

"Don't you touch that shit Eren." Levi cut in, practically throwing invisible daggers into Eren's body with his eyes.

Eren emitted a small, high-pitched yelp and retrieved his hand. "Y-yes sir!"

"Hanji, take your shit alone. No one's going to accompany you so make sure to take a nice, long shit." Levi said with a narrowed gaze. He headed for the door, aiming to leave as swiftly and cleanly as possible.

Hanji was too smart to fall for that. "Here you go, Eren. He's leaving so-"

Before Hanji could carry out her words, Levi snatched the test tube out of her hands. "No experimenting on the brat."

"I thought you were leaving?"

"I am now."

"Nice try, return my test tube."

"No."

"Fine. It's not like I need that one in particular. You can drink that one, and Eren can drink this one."

Levi was silent.

Hanji was grinning.

"What the hell is this damned experiment of yours?" Levi gritted through his teeth.

"There's only one way to find out." Hanji sang, wiggling another test tube in front of his face.

"I'll drink your damned potion but this better not give me explosive diarrhea or some shit."

"Sadly, no."

As Levi brought the test tube up to his lips, Hanji handed Eren a test tube of his own filled with clear blue liquid. She instructed the two to drink it simultaneously, and so to prevent any further trouble they did as told.

Levi finished drinking his share quicker than Eren had, a grimace plastered on his face as he tried to rid of the flavor lingering on his tongue. "What the hell is this anyway?"

"A body swapping experimentation!"

Eren choked on the last bit of the liquid, his eyes boggling out of his head. He nearly dropped the glass, turning to Hanji panic-stricken.

Levi, on the other hand looked a bit more calm but that didn't stop him from looking pissed. "And how long does this last?"

"It ranges from a day..." Eren sighed of relief as Hanji spoke, but she continued. "...to a year."

And now was the right time to carry out with his panic. "A year?" Eren repeated, becoming more worried by the minute. So far, the effects of the potion weren't in toll but there was no telling when it'd start. He began to pace the room, dreading the moment he'd feel his soul slip out of his body and into Levi's. He prayed that Hanji's experiment had been a fail and that he'd only end up having red hair or something like that. Anything but this!

Suddenly, Levi hissed and held his head. He leaned against the wall as his face twisted up in pain. "What the hell's going on, shitty four eyes?" He demanded, his entire body beginning to tremble as seconds ticked by.

"Really? Really, really?" Hanji asked, sounding excited despite Levi's pain. "How do you feel? Like you're being ripped away from reality? Like you're falling asleep?"

Eren didn't have a chance to input on this, because suddenly the world collapsed under him.


	2. Chapter 2

"For the love for all that is fucking holy, what the fuck did you do to me?" Levi demanded.

"I told you. A body swap experimentation." Hanji repeated.

"And you knew this would happen?" Levi surprisingly kept his cool in spite of all the curses that left his lips- well, at this point it was Eren's lips.

"Well I didn't think it would actually work, but if it did work I was ready to be happy!" Hanji said matter-of-factly. "I'm really glad it worked though! I can go so far with this. Maybe we can even try it on the titans and-"

"Turn me back." Levi commanded.

"No."

"Why the fuck not?"

"Because I can't."

"Again. Why the fuck not?"

"I need time to come up with the potion to cancel the effect."

"Then what the fuck are you doing? Get to work."

"You know, it's weird listening to Eren ordering me around. Well, at least you're taller than me now-"

"Get. To. Fucking. Work."

* * *

"Shitty brat you're coming with me." Levi gritted through his teeth as he grabbed Eren by the cravat and dragged him to his office.

To others, it must have looked dangerous and strange. Eren pulling the corporal to his office. What was to ensue? Since when was the corporal under Eren's command?

Levi slammed the door shut behind him, then took a seat on his chair behind his desk. He rubbed his temple, then emitted an annoyed sigh.

"H-heichou what are you-" Eren began to ask, but was cut off by the slamming of Levi's hands onto the desk.

"Take a seat, brat. We got shit to discuss." Levi commanded. "And fix the fucking cravat for shit's sake. What the hell is it doing?"

Eren quickly fixed the cravat with trembling hands, taking a seat on the chair in front of Levi's desk. As offending as it might have been to Levi, Eren felt a bit out of place in the Corporal's body. Everything seemed so much... Bigger?

"As you can see, we're clearly in each others' bodies." Levi said, knotting his fingers together on his desk. "We can't let people find out who we are. And so, in front of others we have to pretend nothing happened. Meaning you're going to have to go to meetings and shit, and pretend to be me."

"I can't possibly do that! I don't even know how deal with paperwork!" Eren cried.

"Don't use that pitiful tone with my voice." Levi warned. "It'll be fine. I'll pretend to be you, and you'll pretend to be me. You and I will share this office during the time we're in each other's bodies, but we'll sleep in our respectful-" He cut himself off, sucking his teeth in disgust. "We'll share a bed as well because hell to the fucking no am I letting my body sleep in a basement, or actually sleep in the basement myself. We'll share my room and my office. To hell with the others who might get suspicious of our behavior. I just don't want them to find this shit out."

Eren didn't know what was more unfortunate. Him being stuck in Levi's body, or him having to share rooms with the Corporal. Would he make it out alive?

"But obviously I can't do the fucking talking for you in meetings, nor can I sign things for you with others in the room so you'll have to learn my signature and the way I deal with things." Levi said, picking up a pen and flicking his wrist to motion for Eren to come over.

Eren complied and went over, stopping in front of the desk.

"Get the fuck over here Yeager I'm not going to frickin' have you fuck up my signature."

Eren quickly walked over to stand behind Levi's seat, leaning over some to get a look at the paper.

"Right. This is my signature so you better not mess up. I'll be in the room when they come in with things to sign. They'll probably give an explanation of the document, and I'll tell you whether to approve or not. You'll sign if I approve, and not if I don't. Easy enough, right? Now let me hear your Corporal Levi imitation. Give me all you got. I'm giving you a chance to make fun of me."

Eren hesitated in opening his mouth, looking to Levi in fear. It was strange to see himself speaking from outside of his own body. It was nearly traumatizing. Levi didn't move from his seat, looking at Eren in expectation.

"I'm not going to fucking make fun of you, shitty brat." Eren said in his best Corporal imitation, feeling his cheeks heat up.

"...Not bad. Practice my signature and everything else should be fine. Also, you're bringing me to meetings with you because I'm not having you build up suspicion when you say stupid shit. Got it?"

"Y-yes sir."

"One more thing I'm going to establish. This body?" Levi grabbed the front of his shirt- Eren's shirt. "Is mine from now on." He then reached forward and grabbed Eren by the hem of his-Levi's shirt. "This body is also mine. I don't fucking care what the fuck you have to protest, from now on, both bodies are mine."

Eren didn't know how to react, opening his mouth to speak only to find himself speechless.

"No objections? Good. Wasn't going to allow any anyway. Dismissed."

* * *

Once Eren moved all of his clothes to Levi's room, he looked helplessly to the Corporal for his next instructions. He was too afraid to move, fearing that he'd get hit for making the wrong move.

"Jesus fucking Christ you literally don't have a single decent piece of clothing do you?" Levi picked through Eren's clothes, pinching them with his index finger and thumb.

"I-I apologize."

"I hope you know, you're not sleeping on my bed without showering. You're not allowed to go to bed without properly bathing my body. You're not allowed to dirty my bed at all." Levi said strictly. "And don't feed my body shit. I better not return to my body and see that my weight went up on the scale. I'll castrate you."

Eren's eyes widened a fraction, and felt tempted to cover his crotch. Except he couldn't, because it was technically Levi's crotch.

"I don't care about what time you sleep, but every morning we're waking up at five and working out. Got that?"

Eren groaned internally, but nodded on the outside.

"And just to let you know, I'm not going to talk to any of your friends so don't complain that you lost your friends-"

"Hey that's not fair! I have to interact with your accomplices but you won't even talk to mine? They'll get mad at me!"

"Gee, Mikasa. Corporal Levi is the best. So hot."

"I won't ever say that."

"Corporal Levi and I live together now."

"DON'T TELL MIKASA THAT!"

"Exactly, brat. So I'm going to ignore your friends. Including Ackerman." Levi concluded. "And it's nice to know you don't think I'm the best, or hot. How freaking considerate of you."

"It's not like I don't think you're cool or attractive..." Eren trailed off.

"Oh?" Levi's eyebrows raised. "Then what do you think of me?"

"Why does it matter?"

"Doesn't."

"Then I don't need to tell you."

"Brat."

"Corporal."

"Tch, you're rather sticky aren't you?" Levi muttered in distaste, moving a stack of paper to the front of him.

"I didn't realize." Eren said truthfully.

"The more you know." Levi said sarcastically, reading over one of the papers in front of him, pen in hand.

* * *

A week felt like forever. It took about an eternity to pass, and Eren thought that he would get busted. Luckily, if someone did suspect him, they didn't say so. They didn't dare speak against the Corporal even if he was acting weird.

Levi on the other hand didn't seem to have a single problem being inside Eren's body. Now that he was no longer full-time a corporal, he had a lot of free time in his hands. Which meant he could clean more often.

And even when Mikasa had approached him once, asking why he was ignoring her, Levi managed to stay in character and told her that she wasn't his mother, and he wasn't ignoring her.

Erwin, who was closest to Levi aside from Hanji didn't suspect a thing. Or at least, Eren hoped so. Erwin went about talking to Eren about important expedition plans and such, and the days went by without anything bad.

Overall, Eren and Levi were proud of each other for playing each other's roles well without flaws. In fact, this whole incident brought the two closer.

Levi still made his toilet jokes and kept his sailor's mouth, but Eren could tell they were getting used to each other. Levi's insults to Eren were actually kind of amorous now. Or he could just have gotten used to it.

"What was the meeting about?" Levi asked, walking into his office while removing his shirt. Levi didn't seem to have a problem removing clothing from Eren's body at all, doing whatever he wished with it. He really was treating Eren's body like his own.

Eren was a whole new story. Eren had been reluctant to take a shower at first and that resulted in a huge argument with Levi. Naturally, Levi won. That still didn't change the fact that Eren respected the corporal's privacy, and didn't want to look at things he wasn't supposed to look at (except he was given permission, so he was allowed).

At the end, Levi said they should shower together because A) That would be fair to the both of them. They would be seeing each other's bodies (which meant, their own original body) and assure that nothing strange happened (Levi said that Eren was a horny teenager who would masturbate with his new body, Levi's body, to which Eren tried to deny. It was unsuccessful). B) Levi didn't trust Eren to properly wash his body.

Their first shower together was awkward and dreadfully long. The whole time Eren washed Levi's back (on his original body), Eren tried to keep his eyes closed but much to his dismay Levi snapped at him and insisted that Eren kept his eyes quote, unquote 'wide' open. Sometimes Eren thought the corporal was doing things on purpose to torture him.

Thankfully, there were days where they couldn't shower together. On those days, Eren made sure to respect Levi's privacy by squeezing his eyes shut and cleaning himself. Luckily Levi never checked to see how clean Eren showered. That went on for a couple of days.

However, as all good things don't last long, Eren wasn't able to avoid seeing Levi's body for long.

* * *

The day started out normal enough.

At five AM in the morning, Eren was forced awake by Levi and dragged out of the room to exercise in the cold morning air. The exercise consisted of the usual, a few sets of push-ups, sit-ups, and an hour of jump roping (Eren stopped to rest when he thought the corporal wasn't looking). After that came their next morning routine of the usual hygienics, and getting changed into clothes more appropriate to get them through the day.

Later in the afternoon was when things began to get a little strange for Eren.

Levi looked distracted during the majority of the morning, often pacing back and forth in his office, only to sit down and think when he decided that pacing wasn't going to help him get to his answer.

Up to that, Eren didn't mind it much. Sure, Eren was concerned for him but it didn't seem like it was anything serious. This was probably what the corporal did aside from cleaning or doing his job.

But that part wasn't what bothered the shifter so much.

While cleaning the floor of Levi's office, he felt a pair of eyes on him and he couldn't help but turn to confirm it with his own eyes. Indeed, the corporal had his gaze locked on Eren and didn't bother looking away even after being caught looking.

Eren ignored it at first and continued on with his work. The last thing he needed was an annoyed corporal on his case, demanding that he cleaned the floors again.

Levi didn't stop looking at him.

No matter what crevice of the room that Eren went to, Levi's eyes followed. When Eren stood up, Levi's eyes rose up with him and went down when Eren got on all fours. Eren began to think he was doing something wrong, and that the corporal was just waiting for the right moment to strike. That wasn't the case at all.

An hour passed and at last Eren was finished with his first task of the day. Thinking he would be able to escape the uncomfortable stares from Levi, he quickly attempted to scramble out of the room and into the kitchen to get some water. He felt as parched as a camel after a long walk.

Levi didn't let that happen. Easily side-stepping, he blocked the door with his body and looked down at Eren with Eren's turqouise eyes. Eren had never felt so intimidated in his life, looking into his own eyes. All of a sudden, his own eyes looked foreign and imcomprehensible.

Eren took a nervous step back, dropping the wash cloth from his hands. He felt something twist in the pit of his stomach and before he knew it, the back of his feet hit the wooden frame of the bed and the momentum caused his knees to buckle. He fell back onto the mattress after losing his balance, his pupils dilating in his lack of knowledge of what was going to occur next.

"Shirt off, brat."


End file.
